Electrolytic process and product.



M. lvl. MERRITT. ELECROLYTIC PRQCESS AND PRODUCT.

PLICATION FILED NOV- 2.1917.

1,282,265.. Patent-,ea oon 22, 1918.

' in) electrolytic processes and more particularly, 15.

y a a ini 'ran salaries rarnnrrrioa MATTHEW M. MERRITT, 0F SOUT MIDDLETON, MASSACHUSETTS, ASSIGN OR TO COPPER 'PROD'UOTS COMPANY, oF BOSTON,

MASSACHUSETTS, A CORPORATION 0F MAINE.

ELECTROLYTIC PROCESS AND PRODUCT.

Specification `of Letters Patent.

Patented oet. 22, i918.

l Application led November 2, 1917. SerialNo. 199,809.

To all whom t may concern:

Beit known that I, MATTHEW M. MERRITT, va citizen of the United- States, and a resident .of South Middleton, county of Essex, Commonwealth offMassachusetts, have invented an Improvement e inv Electrolytic Processes and Products (B), of which thefollowing description, in connection with the accompanying drawings, -is .a specification, like characters on the drawings representing like parts.

This invention pertains to improvements products, and though not exclusively, to improvements in the. manufacture of arti! cles, such as aeroplane propellers formed of non-conductive materials and coated' with electrolytically deposited metal.

In the drawings that show one `formof an illustrative embodiment of my invention:

y Figure l shows an aeroplane propeller coated with copper;

Fig 2 is a 7diagrammatic section therethrough on the line 2-2 of Fig. l,

I have found in electrolytically depositing metal `on the surface of non-conductive bodies that the usual method of applying a paint of granular electrically conductive particles and a binder to the surface of the article to be coated,v and subsequently electrolytically depositing metal such as copper on the surface of the electricallylconductive coating, the deposited metal, partaking of. the structure of the electrically conductive coating, is coarsely crystalline, very brittle, and of apparently slight tensile Strength. I have found that the texture of the deposited copper may be greatly improved, its brittle ness decreased and its tensile strength increased, by interposing between the initial electrically conductive coating and the copper deposit a film orstrata of foreign substance such as grease. I believe that this improved result is due to the equalization of attraction of the entire surface of the cathode. Where the deposit is made directly on the granular coating, each particle of the coating exerts .a considerably greater attraction for the ions vin the bath than is exerted bythe interstices between the grains, thereby separating the copper deposit in coarsely crystalline formation. When, on the other hand, a film of grease is interposed between the entire surface of the granular electrically conductive coating and the electrolyte, the y,

non-conductive cathodes.

rupting the electrolytic deposit at any desired time and coating the surface of the attraction exerted by an exterior projecting I point of each individual grain of the initial copper theretofore deposited with the grease. I believe this to be of advantage in articles which are flexible, notably aeroplane propellers. It is also of advantage because any tendency of the metal to become crystalline' as deposit continues becomes checked. Thus if, for any reason, a portion of the surface of a layer of copper has accumulated occluded hydrogen and has thereby been rendered more cyrstalline in structure, a film of the grease will prevent subsequent deposits nof metal from partaking ofthe coarsely crystalline structure of the underlying surface.

I have described in a co-pending-applica! tion a method of utilizing mercury to secure strong, close-grained metallic deposit on The present invention may be advantageously combined with the invention disclosed in said co-pending application by coating with grease or similar substance the initial application of electrically conductive paint, electrolytically depositing the first layer of metal thereon, coating said layer of metal with the mercury and then electrolytically depositing the second layer of metal either with or without a lm of grease on top of the mercury deposit. For some purposes, if the deposit of successive laminations is to be continued, I prefer from this point on to secure the lamination by means of grease rather than by means of the mercury. l

It will be understood' that I have used the word grease throughout the specification and claims in a generic sense to include any non-conductive substance capable of forming a film over the conductive surface of a cathode.

While I have shown and described one embodiment of my invention and a preferred method of practising the same, it

y will bef-understood that great changes may be made therein Without departing from the scope 'of vmy invention, which is best defined in the"y following claims.

Clainisz' 1. article having a non-conductive core, a layer of granular lelectrically conductive material exterior to'said core, :a layer -of non-conductive foreign substance exterior tosaid coating of granular electrically con- 'ductive material, and a layer of electrolytically deposited; metal exterior to said said core, a ,coating of electrolytically deiforeign substance.

, 2. An article having a non-conductive core, a layer of granular electrically conductive material exterior to said core, a film of Agrease exterior to said coating of granular electrically conductive material and a layer of'electiolytically deposited metal ex- -terior to vsaid grease.

3. A flexible article having a non-con ductive core, a'vlayer of granular electrically conductive material exterior to said core, a film of grease exterior to said coating of granular electrically conductive material and a layer of electrolytically deposited metal exterior to said grease.

4. An aeroplane propeller-having 44a nonconductive core, a layer of granular electrically conductive material exterior to said core, afilm of grease exterior to said coatin of granular electrically conductive materiail y and a. layer of electrolytically deposited metal exterior to said grease.

5. An article having a core of non-conductive material, a coating of granular electrically conductive material exterior to said core, a coating of electrolytically deposited' metal exterior'to said granular coating, a

film of grease exterior to said electrolytically deposited metal, and a second coating of electrolytically deposited inetal exterior to said grease.

6. `A flexible article having a core of non-` conductive material, a coating of granular electrically conductive material exterior to posited metal exterior to said granular coating, a film of grease exterior to said electrof lytically deposited metal, and a second coating of electrolytically deposited metal exterior to said ease.

7. An aerop ane propeller having a core `of non-conductive material, a coating of granular electrically conductive material exterior to said core, a coating of electrolyti- Acally deposited metal exterior tosaid granular coating, a film of grease exterior to said electrolytically deposited metal, and a secties.

ond coating of electrolytically deposited metal exterior to saidgrease.

8. An aeroplane propeller coated with a plurality of layers of electrolytically depositedjmetal, with) grease interposed between said layers.`

' 9. An aeroplane propeller coated with 'a plurality of layers-,of electrolytically deductiveJ article coated with a pluralityv ofelectrolytically deposited metallic laminae,

said laminae being separated by 'a substance electrolytically having relatively slight adhesive or cohesive.

properties.

14. An aeroplane propeller electrolytically coated with a plurality of electrolytically deposit-ed metalliclaminae, said laminae being separated by a substance having relatively slight -adhesive or cohesive proper- 15.- electrically An article covered with a granular conductive surfacing material,

having a layer of metal electrolytically deposited exterior material, said `layer of. metal having an exterior application of a foreign substance anda second coating of electrolytically deposited metal exterior to said foreign substance.

v16. An aeroplane lpropeller coated with a plurality of layers of electrolytically deosited metal with a foreign substance inter- Eosed between said layers. i i' 17. An article coated with a plurality of layers of electrolytically deposited metal with a foreign substance interposed between said layers.

18. AAn article having a shell composed ofv a plurality of layers of electrolytically deposited metal with a foreign substance interposed between said layers. In testimony whereof, I have signed my nameto this specification.

MATTHEW M. MEitRiTT.

to said granular surfacing 

